The latest polls are released as the Clinton team works to contain damage from the FBI's latest email investigation.

The Washington Post-ABC News poll has Mr Trump on 46 percent to Mrs Clinton's 45 percent support – a one-point lead which is within the poll's margin of error.

When third-party candidates are asked which major-party candidate they lean towards, the margin is 48-47 to Mrs Clinton, the Washington Post said of its poll, which was carried out from Thursday to Sunday.

A Los Angeles Times poll just out gives Mr Trump a four-point national advantage.

However other polls have Mrs Clinton in the lead.

The BBC's poll of polls, puts Mrs Clinton ahead, though with her lead narrowing. The poll of polls looks at the five most recent national surveys and takes the median value.

And the latest Reuters/Ipsos poll on Monday gave a 44-39 lead to Mrs Clinton.